The sharp rise in Covid-19 infection rates around the world has sparked a scientific and ethical debate over the need for booster vaccines to maintain protection against the virus.
This week, following a spike in cases related to the Delta variant, Israel became the first country to offer boosters, allowing third doses of the BioNTech / Pfizer vaccine to adults with serious pre-existing health conditions. do the same.
But the science as to whether boosters are needed to provide long-term immunity to the Delta variant is so far inconclusive. And the World Health Organization has questioned the ethics of administering third injections, as billions of people in low-income countries still await their first injection.
Rajiv Shah, president of the Rockefeller Foundation, said he expected Covid booster injections to be needed in the years to come as the virus continues to circulate, much like with the flu, for which annual revaccination is required.
âThe task of vaccinating the world is not a one-off task,â he told the Financial Times, adding that revaccination âwill be an endemic realityâ.
But it’s unclear if boosters are needed now. Studies conducted in May by Public Health England in the UK, where the Delta variant is dominant, found that two injections of the BioNTech / Pfizer injection were still 96 percent effective in preventing hospitalization. Research has identified a decrease in protection against symptomatic Delta infection, but only slight – 88% efficacy versus 93% against the Alpha variant first identified in Kent.
The major manufacturers of jab have all said that the full vaccination should provide immunity for at least six to 12 months. This week, Johnson & Johnson said interim results showed its single-injection vaccine produced a strong immune response eight months after vaccination, including against the Delta variant.
Other studies, however, have suggested that the immune response generated by many of the current vaccines may last longer. Researchers at the University of Washington discovered in June that the mRNA vaccines from Pfizer and Moderna produced “persistent” immunity, with a stronger response in people who had previously been infected with coronavirus and then received an immunity. complete vaccination.
“The reason for a recall would be … the emergence of a new variant to which the immune response of a vaccine no longer covers it,” said Michael Saag, associate dean of global health at the University of Alabama to Birmingham. “At the moment I don’t see that,” he said, adding that the number of vaccinated people falling seriously ill from Covid had not increased significantly.
Major pharmaceutical companies appear to be in favor of fast boosters, with Pfizer and Moderna pushing the most vocally for the use of third shots.
Last week, Pfizer said it plans to apply for emergency use authorization in August from the U.S. Food and Drug Administration to give people a third dose. The announcement prompted an immediate reaction from the FDA and the Centers for Disease Control, who said in a joint statement that fully vaccinated people “do not need a booster at this time.” “[We are] prepared for booster doses if and when science shows they are needed, âthe agencies said.
The boosters market presents a huge opportunity for the pharmaceutical industry, with analysts anticipating tens of billions of dollars in revenue for Moderna and Pfizer alone.
In the UK, the government’s Joint Committee on Vaccination and Immunization recently issued an interim opinion that millions of the most vulnerable people, especially the elderly, who tend to have weaker immune responses, should be revaccinated in the fall. The final decision on whether or not to allow the booster campaign will depend on the results of ongoing studies into the duration of protection provided by the vaccines, the UK said.
Azra Ghani, president of infectious disease epidemiology at Imperial College London, said it was “pragmatic” for the UK to plan ahead given its plentiful supply of doses.
Two-thirds of the UK’s adult population have been fully vaccinated and the government is still awaiting doses from its original purchase contracts with Novavax and Johnson & Johnson, in addition to additional Pfizer vaccines ordered earlier this year. The EU is also preparing to administer recalls, having ordered 1.8 billion doses of Pfizer to be delivered from the end of this year through 2023.
The EU said it could donate any surplus. Yet Tedros Adhanom Ghebreyesus, director-general of the World Health Organization, this week criticized rich countries for ordering additional injections, while large swathes of the developing world cannot afford even the first doses.
âThe global gap in the supply of Covid-19 vaccines is extremely uneven and inequitable,â Tedros said. “Some countries and regions are actually ordering millions of booster doses, before other countries have had supplies to immunize their health workers and the most vulnerable.”
Nearly half of the United States is fully vaccinated, compared to less than 2% of Africa’s total population, according to the WHO.
“This is really of ethical concern,” said Michael Carome, director of the health research group of advocacy group Public Citizen. “The real goal should be to distribute the vaccine to the countries where they are lagging behind, because in the end it will protect everyone.”
Ghani, of Imperial College London, said the decision to strengthen or not was ultimately an act of political balancing.
For each country, “there really is no harm in giving a booster dose,” she said. However, globally, âthese vaccines could possibly save more lives if given in first and second doses to people who did not receive them. And of course, that would have the advantage of reducing transmission and making this country safer â.